1. Field of the Invention
The present invention relates to a moving mold mechanism of a pipe bending machine, more particularly one, which includes two fixed molds, bending wheels on each fixed mold, two moving mold seats facing respective fixed molds, several pressing wheels on each moving mold seat, rotating power source, a roller having spiral grooves and connected to the rotating power source for transmitting motion to the moving mold seats, and guiding mechanisms and linear rail mechanisms for making both the moving mold seats moved forwards and backwards in crossing directions respectively as well as upwards and downwards in a sloping path respectively so as to carry out a pipe bending process and to end a pipe bending process.
2. Brief Description of the Prior Art
An early pipe bending machine includes a pipe feeding mechanism, a fixed mold, a bending wheel secured on the fixed mold, and a moving mold mechanism, which consists of a mold seat member, and a pressing wheel on the mold seat member. In use, a pipe is fed between the bending wheel of the fixed mold and the pressing wheel of the moving mold mechanism by means of the pipe feeding mechanism, the mold seat member is moved about the bending wheel by means of a power source for the pressing wheel to bend the pipe into a certain curve together with the bending wheel. The user has to replace the current bending wheel and pressing wheel with different-sized ones every time before a pipe is bent into a curve with a radius different from that of the last pipe. Therefore, such pipe bending machine isn't convenient to use.
To overcome such inconvenience, an improvement on a pipe bending machine is equipped with a fixed mold, several different-sized upper bending wheels and several lower bending wheels on the fixed mold, upper and lower moving mold seat members, and two power source mechanisms for moving respective ones of the moving mold seat members; each moving mold seat member has several different-sized pressing wheels positioned thereon. The upper pressing wheels face and work with corresponding upper bending wheels of the fixed mold for bending pipes into curves with different radiuses while the lower pressing wheels face and work with corresponding lower bending wheels for bending pipes into curves with different radiuses. Therefore, the use doesn't have to replace the bending wheels and the pressing wheels with different-sized ones.
However, because the pipe bending machine is equipped with two power source mechanisms for moving the upper and the lower moving mold seat members respectively, its manufacturing cost is relatively high. Furthermore, because the power source mechanisms are positioned parallel to the moving mold seat members, the moving mold seat members are prone to be interfered with when they are moving away from the bending wheels at the end of a pipe bending process.